1. Field of the Invention
The present invention generally relates to a balloon catheter and its method of use, and more particularly, concerns a detachable balloon catheter device useful for occluding vessels, such as blood vessels, in the human body.
2. Description of the Prior Art
Balloon catheters have been used for many years to carry out medical procedures in blood vessels, body cavities and the like. Detachable balloon catheters, however, are rather recent developments directed to more particular medical procedures related to vascular occlusion or the like interventional techniques. Some of the early work in detachable balloon catheters is traced to pioneering activities of F. A. Serbinenko, M.D., and Gerard Debrun, M.D. See, e.g., Serbinenko, F. A., "Balloon Catheterization and Occlusion of Major Cerebral Vessels," Journal of Neurosurgery, Vol. 41, pp. 125-145, Aug. 1974, and Debrun et al., "Inflatable And Released Balloon Technique Experimentation In Dog--Application In Man," 9 Neuroradiology, p. 267, 1975. Additional activities were carried on in the 1970's by Paul Pevsner, M.D. See, e.g. Pevsner, P. H., "Micro-Balloon Catheter For Superselective Angiography And Therapeutic Occlusion," 128 American Journal of Roentgenology, p. 225, 1977; and U.S. Pat. No. 4,085,757.
A significant use of detachable balloon catheters is in the therapeutic occlusion of arteries. For instance, detachable silicone balloons have been employed for therapeutic embolization by R. I. White, M.D. See, e.g., White et al. "Therapeutic Embolization With Detachable Silicone Balloons," 241 Journal of the American Medical Association, pp. 1257-1260, Mar. 23, 1979. Detachable balloon catheters have also been used for carotid-cavernous sinus fistulas and other AV fistulas in the head. Dr. White has also employed a detachable balloon catheter for the occlusion of the internal spermatic vein in the treatment of varicoceles. At present, a detachable balloon catheter is available from Becton, Dickinson and Company, Rutherford, New Jersey, known as the B-D MINIBALLOON.TM. Detachable Balloon System.
One of the difficulties encountered in utilizing a detachable balloon catheter device lies in the detaching function. Initially, the inflatable balloon is attached to an introducer catheter or like cannula, and by angiographic techniques, the balloon and cannula are inserted into the artery until the balloon reaches the desired site. The balloon is inflated at that site by pressurized fluid entering the balloon through the cannula. Thereafter, it is desired to leave the inflated balloon in position while detaching the cannula. Difficulties arise because the cannula must be detached from the balloon, located at a remote site in the body, while the balloon remains in position, and inflated. Various techniques have been proposed to assure this capability of detachment while leaving the balloon inflated in situ.
One recent suggestion for improving the detachment capability of detachable balloon catheters is found in U.S. Pat. No. 4,311,146. This patented device relies upon longitudinal expansion of the balloon in the blood vessel to literally pull a valve longitudinally into the balloon inflating passage after the balloon has been inflated with sufficient fluid. The movement of this valve is described as being achieved automatically to effect a closure of the inflated balloon, whereupon the introducer catheter may be detached. It should be pointed out, however, that such automatic closure of the inflated balloon deprives the operator of flexibility in the manipulation of the balloon if it should be inflated inadvertently or if adjustments may be required in the location of the balloon at a remote site in the body. Accordingly, in this rather new field of detachable balloon catheters, improvements are still being sought which contribute to the ability to inflate the balloon, detach the catheter therefrom, while assuring that the inflated balloon remains inflated at the desired site. In addition, ease of use, simplicity of structure, economies of manufacture and operator training are factors which must be considered when improving a detachable balloon catheter device. It is to such improvements that the present invention is directed.